Dilatometry may be used on cold rolled plates to determine the temperatures of phase transformations and the volume fractions of phases formed after continuous annealing simulations. The state of deformation in cold rolled plates was responsible for a decrease in the kinetics of austenite formation during annealing between Ac_1 and Ac_3. Continuous annealing simulations with different cooling patterns were performed on cold rolled plates, and the tensile properties were measured. The effects of the different parameters can be summarized as follows.A ferrite-pearlite starting microstructure leads to lower tensile strengths and better elongation after annealing due to the shape of ferrite. However, due to the higher transformation of pearlite to austenite than ferrite to austenite, a banded structure is still present after annealing and may be detrimental for the tensile properties in the transverse direction. A bainite-martensite starting microstructure leads to higher strength levels but poorer elongations.Increasing the annealing temperature leads to the formation of more austenite. Hence, according to the cooling pattern, more hard phases bainite and martensite are formed, increasing the strength level. More recrystallization of the ferrite may be responsible for excellent elongation.Austenite formation was faster at the start of the intercritical annealing. Carbon partitioning took more time. Reducing annealing time leads to slightly lower fractions of austenite formed.The best compromises between high strength and good elongation were obtained for CP steel with about 63 percent ferrite, 25 percent bainite and 12 percent martensite. Thermal cycles which include an isothermal bainitic transformation holding were the most efficient.
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